import dascore as dc
patch = dc.get_example_patch()
# perform dft (fft) on time axis
dft_time = patch.dft(dim="time")
# get inverse dft, transformed axis are ascertained automatically
idft = dft_time.idft()idft
idft(
patch: Patch ,
dim: str | collections.abc.Sequence[str, collections.abc.Sequence[str], None] = None,
)-> ‘PatchType’
Perform the inverse discrete Fourier transform (idft) on specified dimension(s).
Currently, only patches that have been transformed with dft can be used with this function. After transformation with dft, the transformed coordinates cannot change (e.g., with select otherwise idft won’t work.
Parameters
| Parameter | Description |
|---|---|
| patch | Patch to transform. |
| dim |
A single, or multiple dimensions over which to perform idft. If None, perform idft over all dimensions that have names starting with “ft_”, which indicates they have already undergone a fourier transform. |
Note
Real transforms are determined by transformed coordinates which have no negative values.
Non-dimensional coordinates measured on a transformed dimension are restored with it, provided the patch still carries what dft parked for them. One spanning more than one dimension is not parked, so it does not come back.
See the FFT note in Notes section of DASCore’s documentation.